CVE-2026-43376: Linux Kernel

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using call_rcu() for oplock_info ksmbd currently frees oplock_info immediately using kfree(), even though it is accessed under RCU read-side critical sections in places like opinfo_get() and proc_show_files(). Since there is no RCU grace period delay between nullifying the pointer and freeing the memory, a reader can still access oplock_info structure after it has been freed. This can leads to a use-after-free especially in opinfo_get() where atomic_inc_not_zero() is called on already freed memory. Fix this by switching to deferred freeing using call_rcu().

Affected products

• Linux Linux Kernel: from 6.6.88, before 6.6.130 (fixed in 6.6.130); from 6.12.25, before 6.12.78 (fixed in 6.12.78); from 6.14.4, before 6.15 (fixed in 6.15); from 6.15.1, before 6.18.19 (fixed in 6.18.19); from 6.19, before 6.19.9 (fixed in 6.19.9); version 6.15 only; …

Published 2026-05-08. Last modified 2026-06-17.